Piner Creek

Piner Creek is a stream in northeast Santa Rosa, California, United States (38°27′40″N 122°45′05″W / 38.46111°N 122.75139°W / 38.46111; -122.75139) which originates as an outlet of Fountaingrove Lake. Piner Creek discharges to Santa Rosa Creek which in turn joins the Laguna de Santa Rosa. The upper reaches in the foothills of the Mayacamas Mountains are at elevations of 200 to 300 feet (60 to 90 meters), while the lower and middle reaches are located on the Santa Rosa Plain at elevations of between the 110- and 140-foot (33- and 43-meter) contours; therefore, these lower reaches have a gradient of about 1:250 toward the southwest. Geologic studies in the lower and middle reaches of Piner Creek indicate groundwater levels ranging from three to 15 feet (one to 5 meters) below the surface. Prior to extensive urban development of the middle and lower reaches, the landscape earlier bore extensive agricultural uses including plum orchards, which fruit was subsequently processed for prunes.

The Piner Creek watershed consists of 4,048 acres (16.4 km²), approximately three-fourths of which lies within the municipal boundaries of the city of Santa Rosa. About one-third of the watershed is developed as residential use, and about one-sixth of the land is open space or used for recreation or agriculture. One of the early surviving architectural features of Sonoma County is within the Piner Creek catchment basin: A well preserved Round Barn, constructed in 1899, a testament to the 19th century pasturage uses within this watershed.